Bill Buxton's Notes

The RollerMouse Pro is a pretty interesting input device. First developed in 2004, and the version that I have in 2005, its main purpose is to permit the normal functions of the mouse, such as pointing, scrolling, selection and dragging, while avoiding the need to move the hands away from the keyboard.

While several other technologies, such as touch pads, trackballs and miniature joysticks have been used to accomplish this, the RollerMouse Pro takes a fairly unique approach. Like many of these devices, it is centrally located laterally relative to the QWERTY keyboard. However, it is integrated into a palm rest, such as you would and could add to a conventional keyboard â€“ hence, it can be retro-fitted to many or most keyboards.

The heart of the device is a roller of about 4 cm diameter that is mounted horizontally parallel to the rows on the keyboard. About 17 cm of the roller is exposed. Rotating the roller moves the screen cursor up and down. Sliding the roller left and right (there are about 9 cm total travel possible) moves the cursor horizontally. The roller is surfaced in rubber, which means that it has good friction with the hand, and can be easily moved either horizontally, vertically, or both simultaneously in order to get diagonal motion.

One consequence of this design is that it is easy to use either hand for scrolling, thereby distributing the load. Furthermore, there is a centrally mounted scroll-wheel below the bar which is positioned so as to be operated by either thumb, meaning that it is possible to operate with a different hand than that doing the pointing.

There are three large buttons, easily accessed by the thumb, mounted below the scroll wheel. The left one serves as the left mouse button signal, something that can also be signaled by just pushing down on the roller bar. The large central button is like an accelerator for double clicking â€“ you get the signal through a single push.

The large right-side button serves the normal function of the mouse right-button click, such as brining up a utility pop-up menu for cut, paste, copy, etc.

Finally, there are two smaller horizontally-mounted buttons between the roller-bar and the scroll wheel. The left one locks the roller-bar into scroll mode so that you can use if for scrolling in lieu of the scroll wheel. The other is used to anchor the selection point when you want to sweep out some text, for example. The benefit here is that you do not need to keep your hand or finger in a state of tension holding down a button during the dragging process.

While both uncommon and largely unknown outside of those who are suffering from RSI, there is an interesting history to this class of device. Back in the late 1980s, a designer named Craig Culver developed a roller-bar device which was called the Isopoint, and was built by Alps Electric. Besides being yet another example of how such ideas evolve, the historically point of interest is that the Isopoint roller device was used on the very first PC laptop to have an integrated pointing device that was mounted front and center of the keyboard (the GRiDCASE 1550sx, introduced in November 1989). As with the RollerMouse Pro, this made it possible for both right and left-hand users to operate (something that virtually all laptops enable today).

There is at least one other device that uses the Isopoint-type roller-bar. It made in Sweden and is known as the Nomus Navigator: